Megan Fellman, reporting for Northwestern University in Evanston, Illinois, explains a possible breakthrough in obtaining power conversion efficiency for polymer (plastic) solar cells close to those for more expensive silicon cells. Fellman lists the benefits of the plastic cells: “Among the various photovoltaic technologies, polymer (plastic) solar cells offer unique attractions and opportunities. These solar cells contain Earth-abundant and environmentally benign materials, can be made flexible and lightweight, and can be fabricated using roll-to-roll technologies similar to how newspapers are printed. But the challenge has been improving the cells’ power-conversion efficiency.” Faculty members and students led by Professor Tobin J. Marks designed and synthesized new polymer semiconductors, “and reports the realization of polymer solar cells with fill factors of 80 percent – …